1) Scope of the invention
The cosmetics and health industry has for a long time been searching for relatively not onerous packagings capable of delivering their content, without requiring the use of excessive force by the user, and which maintain a pleasing exterior aspect until the end of their existence.
A well known problem of packaging of paste material, notably in cosmetics, but equally in other technical fields, is to limit in as far as possible the contact of the content with the ambient air, which accelerates the degradation of certain constituents. Containers in malaxable materials (metallic tubes) rapidly present a less attractive appearance. Rigid containers easily resume their form by sucking in air which replaces the paste which has just been extracted therefrom, which constitutes an inconvenience from the point of view of the degradation of the content and of its asepsis. New forms of packaging have been developed to avoid the inconveniences.
2) Description of the anterior art
The patent U.S. Pat. No. 4,842,165 describes an elastic walled bottle in which a pouch destined to enclose the product to be dispensed is suspended. This pouch is held in position half way up on the elastic wall. A non-return valve prohibits the product from re-descending into the pouch after compression. A second non-return device placed in the base of the bottle permits air to reenter between the bottle and the pouch when the compression has ceased.
The patent U.S. Pat. No. 4,909,416 describes a dispensing recipient of viscous products endowed with an exterior recipient capable of being pressed or deformed locally (structure in accordion) and a deformable interior pouch connected to a nozzle. This nozzle comprises a unidirectional valve prohibiting the reflux of the content towards the pouch. A second valve permits the introduction of air between the pouch and the exterior recipient.
A characteristic common to the recipients described in these two documents is vested in their relative complexity. These devices utilize relatively complex valves and interior and exterior envelopes which are manufactured distinctly and assembled for use. The cost of such recipients is therefore relatively high and is only justified for relatively onerous products or for particular uses.
A market exists for dispensing packagings for paste products which, while fully benefitting from the intrinsic qualities of this type of packaging, could be produced at a relatively low price.